1. Field of Invention
The invention pertains to azeotrope-like compositions of 1,1,2,3,3-pentafluoropropene (HFO-1225yc) and any one of 1,1,1,2-tetrafluoropropene (HFO-1234yf) or the Z-isomer of 1,1,1,2,3-pentafluoropropene (HFO-1225yeZ), and uses thereof.
2. Description of the Related Art
Fluorocarbon based fluids have found widespread use in industry in a number of applications, including as refrigerants, aerosol propellants, blowing agents, heat transfer media, and gaseous dielectrics. Because of the suspected environmental problems associated with the use of some of these fluids, including the relatively high global warming potentials associated therewith, it is desirable to use fluids having low or even zero ozone depletion potential. Thus, the use of fluids that do not contain chlorofluorocarbons (“CFCs”) or hydrochlorofluorocarbons (“HCFCs”) is desirable. Compounds having a low ozone depletion potential include hydrofluorocarbons (“HFCs”), especially hydrofluoroolefins (“HFO's”). Compounds having a low global warming potential are also desirable. In this regard, the use of alkenes is also desirable due to their short atmospheric lifetime which results in a relatively low global warming potential. Additionally, the use of single component fluids or azeotropic mixtures, which do not fractionate on boiling and evaporation, is desirable. However, the identification of new, environmentally safe, non-fractionating mixtures is complicated due to the fact that azeotrope formation is not readily predictable.
The industry is continually seeking new fluorocarbon based mixtures that offer alternatives, and are considered environmentally safer substitutes for CFCs and HCFCs. Of particular interest are mixtures containing hydrofluorocarbons, fluoroolefins and other fluorinated compounds, which have a low ozone depletion potentials and low global warming potential. Such mixtures are the subject of this invention.
U.S. Pat. No. 6,858,571 describes azeotrope-like compositions comprising pentafluoropropene (HFO-1225) and a fluid selected from the group consisting of 3,3,3-trifluoropropene (“HFO-1243zf”), 11-difluoroethane (“HFC-152a”), trans-1,3,3,3-tetrafluoropropene (“HFO-1234ze”), and combinations of two or more thereof. However, U.S. Pat. No. 6,858,571 does not show azeotrope-like composition comprising HFO-1225yc with either HFO-1234yf or HFO-1225yeZ. The invention concerns compositions that help to satisfy the continuing need for alternatives to CFCs and HCFCs. The compositions of the invention exhibit relatively low global warming potentials (“GWP”). Accordingly, applicants have recognized that such compositions can be used to great advantage in a number of applications, including as replacements for CFCs, HCFC's, and HFCs in refrigerant, aerosol, blowing agents, and other applications.